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United States Patent 6,248,726
Alsop ,   et al. June 19, 2001
Method of peritoneal dialysis using glucose polymer solutions

Abstract

There is described polysaccharides of high molecular weight for use in peritoneal dialysis. The polysaccharides are capable of dialysing human serum for long periods of time without causing damage to the peritoneum and are also capable of preventing loss of polymer from the peritoneum to the serum. There is also described a method of making the polysaccharides and pharmaceutical formulations containing them.

Inventors: Alsop; Ranulph Michael (Alderley Edge, GB); Forrester; Raymond Brian (Sandbach, GB); Manning; David John (Congleton, GB)
Assignee: M L Laboratories plc (London, GB)
Appl. No.: 954686
Filed: September 30, 1992
Foreign Application Priority Data
Jun 22, 1985[GB]BA85/15842

Current U.S. Class: 514/58; 514/54; 514/60
Intern'l Class: A61K 031/70
Field of Search: 514/58,60,54

References Cited
U.S. Patent Documents
2823128Feb., 1958Toulmin536/112.
4182756Jan., 1980Ramsay et al.536/1.
4357323Nov., 1982Soma et al.536/1.
4514560Apr., 1985Shinohara et al.536/1.
4886789Dec., 1989Milner514/54.
Foreign Patent Documents
0 153 164Aug., 1985EP.
WO 82/03329Oct., 1982WO.


Other References

Alexander et al., Chemical Abstracts, vol. 98, 1983 No. 149608 K.*
Chemical Abstracts vol. 85, 1976, p. 410 (Reference No. 141580f).
Chemical Abstracts vol. 99, 1983, p. 619 (Reference No. 105608b).

Primary Examiner: Peselev; Elli
Attorney, Agent or Firm: Marshall, O'Toole, Gerstein, Murray & Borun
Parent Case Text


This application is a continuation of application Ser. No. 07/779,129, filed Oct. 16, 1991, now abandoned, in turn a continuation of 06/875,461 filed Jun. 18, 1986, now abandoned.
Claims


We claim:

1. A method of treatment of a human requiring dialysis of the serum by use of an aqueous solution of a physiologically acceptable mixture of glucose polymers derived from the hydrolysis of starch, wherein at least 50% by weight of said mixture comprises polymers having molecular weights in the range of from 5,000 to 30,000, and wherein said mixture has a weight average molecular weight of from 5,000 to 50,000, and a number average molecular weight of from 2,890 to 8,000.

2. A method of treatment in accordance with claim 1 wherein up to 20% by weight of the polymers in the mixture have a molecular weight of from 800 to 10,000.

3. A method of treatment in accordance with claim 1 wherein the mixture contains less than 5% by weight of glucose polymers with molecular weight greater than 100,000.

4. A method of claim 1 wherein the aqueous solution further comprises amino acids.
Description


This invention relates to a new form of polymer, a method for its production and compositions containing it.

Maltodextrins (glucose polymers) are produced by the hydrolysis of pure starch isolated from various natural products, e.g. wheat, rice, tapioca etc. In a typical process a pure isolated starch is produced by a multi-stage separation process involving removal of protein, oil, fibre and glutens before being hydrolysed.

As no single number can adequately characterise the molecular weight of a polymer, such as a maltodextrin, various averages are used. The most commonly used are the weight average molecular weight (M.sub.w) and the number average molecular weight (M.sub.n): ##EQU1##

where n.sub.i is the number of molecules of molecular weight M.sub.i. M.sub.w is particularly sensitive to changes in the high-molecular-weight content of the maltodextrin polymer whilst M.sub.n is largely influenced by changes in the low molecular weight of the sample.

We have now found that it is possible to monitor starch hydrolysis and in particular to stop the hydrolytic action when the hydrolysate contains the maximum amount of molecules in the desired molecular weight range. The monitoring may be carried out by a technique known as size exclusion chromatography. Furthermore, fractionation of the starch hydrolysate can be monitored by size exclusion chromatography and a weight average molecular weight, a number average molecular weight and a molecular weight distribution of the products can be determined using chromatographic columns calibrated with dextran standards (Alsop et al Process Biochem 2 10-15 (1977) and Alsop et al J. Chromatography 246, 227-240, (1982)).

We have also found a method for optimising the yield of a glucose polymer with a preselected molecular weight range.

Glucose polymers are often characterised by the expression "degree of polymerisation" (DP). In this terminology a product may be described as having 20% of its weight comprising molecules with a DP greater than 10, ie. 20% has a molecular weight greater than 1656 (a polymer comprising 10 glucose units).

British Patent Application 2132914A describes a glucose polymer mixture having at least 15% by weight of glucose polymers of DP greater than 12 for use in continuous ambulatory peritoneal dialysis (CAPD). PCT/US Application 82/00774 describes a CAPD solution comprising glucose polymers of DP of at least 4.

European Patent Application 0076355 A2 discloses glucose polymer mixtures having at least 99% of glucose polymers of DP less than 12 for use in CAPD.

It has now surprisingly been found that certain polydisperse glucose polymer mixtures of high molecular weight are useful in medicine, e.g. in CAPD and in prevention of post-operative adhesions.

According to the invention we provide a glucose polymer mixture (I), wherein at least 50% by weight of the polymer is of molecular weight in the range 5000 to 30000.

We particularly prefer a glucose polymer (I), wherein at least 80% by weight of the polymer is of molecular weight in the range 5000 to 50,000.

We prefer the glucose polymer (I) to have a weight average molecular weight in the range of from 5000 to 100000, preferably of from 5000 to 50000, more preferably of from 12000 to 25000, and most preferably of from 14000 to 20000.

We prefer the glucose polymer (I) to have a number average molecular weight of less than 8000, preferably less than 5000, more preferably less than 4000 and most preferably less than 2900.

We prefer the content of mono-, di-, and tri-saccharide compounds present in the glucose polymer (I) to be less than 5% by weight, more preferably less than 2% and most preferably 0% by weight. By 0% we mean an amount which is undetectable by conventional methods.

We further prefer that the content of glucose polymers with molecular weight greater than 100000 in the glucose polymer (I) should be less than 5%, preferably less than 3% and most preferably less than 1% by weight.

We prefer the glucose polymers to be substantially free from endotoxins and nitrogenous contaminants arising from the original starch, or from the enzyme preparations used for its hydrolysis.

We particularly prefer the endotoxin level to be less than 0.25 endotoxin units/ml, more preferably less than 0.12 endotoxin units/ml and most preferably less than 0.06 endotoxin units/ml as determined by the Limulus Lysate Test (US Pharmacopoeia).

We prefer the nitrogen content of the glucose polymers to be less than 0.01% w/w, more preferably less than 0.001% w/w and most preferably zero as determined by the Kjeldahl method (British Pharmacopoeia)

We also prefer the glucose polymers to be substantially free of undesirable metals, e.g. aluminium. Thus we prefer the level of aluminium to be less than 500 ppb, more preferably less than 200 ppb and most preferably less than 100 ppb.

We also prefer an aqueous solution comprising 10% w/v of the glucose polymer to be substantially clear and colourless. Thus we prefer such a solution to have a turbidity value of less than 30 EEL units (US Pharmacopoeia), more preferably less than 20 EEL units and most preferably less than 10 EEL units. We also prefer such a solution to have no substantially visible colour. We particularly prefer the solution to have a visible colour of less than 10 APHA Hazen units and more preferably less than 5 APHA Hazen units. The content of colour precursors such as 5-hydroxymethyl furfural can be measured by absorption of ultraviolet light of wavelength 275 or 284 nm. We prefer the absorbance to be less than 0.5, more preferably less than 0.25 and most preferably less than 0.15. The transmission of ultraviolet light measured at a wavelength of 430 nm is preferably greater than 90% and more preferably greater than 95%.

It is a further feature of this invention to provide a glucose polymer (I) having up to 20% by weight of glucose polymers with a molecular weight of from 800 to 10,000, preferably of from 1500 to 4000. We particularly prefer a glucose polymer (I) having up to 20% by weight of glucose polymers with a molecular weight of from 1500 to 2500, more preferably up to 10% by weight and most preferably up to 7% by weight.

According to the invention we also provide a method for the production of a glucose polymer (I), which comprises

a) fractional precipitation of an aqueous solution of a glucose polymer containing polymer (I) with a water miscible solvent, and/or

b) filtration of an aqueous solution of a glucose polymer containing polymer (I) through membranes possessing an appropriate molecular weight cut-off range. The molecular weight cut-off range may be determined empirically.

In process a) the process parameters used are interdependent and each parameter may vary depending upon the desired quality of the product, the desired molecular weight range, etc. The water miscible solvent may be an alcohol, eg an alkanol, such as ethanol. The solvent may be present in an aqueous solution which is mixed with an aqueous glucose polymer. The concentration of the solvent in the aqueous solution before mixing may be from 60 to 100%v/v, preferably from 75 to 90%v/v, and most preferably about 85%v/v.

The concentration of the aqueous glucose polymer solution before mixing may be from 0 to 80% w/v, preferably from 15 to 65% w/v, and most preferably from 30 to 40% w/V.

The fractionation may be carried out at a temperature of from 10 to 40.degree. C. and more preferably from 20 to 30.degree. C.

In process b) the type of membrane material used may vary with the particular molecular weight distribution which is desired. A chemically inert plastics material may be used for the membrane, eg. a cellulose acetate or polytetrafluoro-ethylene. We particularly prefer to use a material which is mechanically stable at high temperatures and pressures, eg. a polysulphone.

A series of membranes may be used consecutively such that both a high and a low molecular weight fractionation is carried out. The membrane fractionation may be carried out at elevated temperature sufficient to prevent bacteriological contamination. We prefer the fractionation to be carried out at a temperature of from 0 to 90.degree. C., preferably from 20 to 80.degree. C., and most preferably from 65.degree. to 75.degree. C.

The feed solution may be of a concentration of from 1.0 to 30.0% w/v, preferably from 5 to 15% w/v and most preferably about 10% w/v.

The glucose polymer starting material is preferably prepared by a method, e.g. hydrolysis, designed to optimise the proportion of polymer (I), and the progress of that method is preferably monitored by size exclusion chromotography. Any starch may be used in the hydrolysis but we prefer to use a cornstarch.

The molecular weight distribution of the fractions may be determined using the chromatographic techniques described by Alsop et al J. Chromatography 246, 227-240 (1982). The optical rotation of the various solutions produced may also be used to identify the concentrations of the polymer contained by the solutions.

The high molecular weight waste products from the fractionations may be further hydrolysed to produce further quantities of lower molecular weight products which can be fractionated. The low molecular weight waste products may be useful in the production of glucose syrups.

Before, during and/or after the fractionation of process a) or b) the polymer may be purified. The purification may be to remove undesirable colour or to remove contaminants, for example proteins, bacteria, bacterial toxins, fibres or trace metals, eg aluminium. Any conventional purification technique may be applied, for example, filtration and/or absorption/adsorption techniques such as ion exchange or charcoal treatment.

The product of the fractionation of process a) or b) may be packaged and transported as a syrup or solution, for example an aqueous solution. However, we prefer the product to be in a solid form, preferably a powder, and most preferably spray dried granules.

The glucose polymer (I) is useful in a wide variety of medical indications, e.g. peritoneal dialysis, as a nutritional agent or for the prevention of post-operative adhesions etc.

According to the invention we also provide a pharmaceutical composition comprising a glucose polymer (I), wherein at least 50% of the polymer is of a molecular weight in the range 5000 to 30000, in admixture with a pharmaceutically acceptable adjuvant, diluent or carrier.

Any composition for use in CAPD preferably comprises physiologically acceptable electrolytes, eg. sodium, potassium, calcium and magnesium in order to prevent the transfer of desirable electrolytes from the serum to the peritoneum. The amounts may vary depending upon the requirements of any individual patient and are generally sufficient to provide an osmolarity of from about 240 to 275 mOsm/liter (see Example A).

According to the invention we also provide a physiologically acceptable polysaccharide (II) with an osmolarity of less than 160 mOsm/liter, preferably less than 110 mOsm/liter more preferably less than 90 mOsm/liter and most preferably less than 20 mOsm/liter, which is capable of being used in solution in the dialysis of normal human serum. By normal human serum we mean serum with an osmolarity of between 280 and 290 mOsm/liter at 37.degree. C. The polysaccharide (II) preferably has the molecular weight and other parameters described above with respect to glucose polymer (I). Any suitable polysaccharide may be used but we prefer the polysaccharide to be a glucose polymer (I).

The polysaccharide (II) may be prepared by any of the processes hereinbefore described or by conventional processes known per se.

We also provide a composition capable of dialysing normal human serum comprising a polysaccharide (II) and having an osmolarity somewhat greater than normal serum. The osmolarity of the composition is preferably less than 400 mOsm/liter, more preferably less than 350 mOsm/liter and most preferably less than 330 mOsm/liter at 37.degree. C. We particularly prefer a composition with an osmolarity less than 300 mOsm/liter at 37.degree. C.

The composition may be in solid form, eg suitable for extemporaneous production of a solution, or it may be a liquid, eg in the form of an aqueous solution. The composition preferably includes pharmacologically acceptable electrolytes. Such electrolytes may include appropriate ions, eg of sodium, potassium, calcium, magnesium and chloride; buffers, eg. lactate, acetate or bisulphite; or other additives, such as amino acids, polyols or insulin.

The polymer (I) and the polysaccharide (II) are advantageous over the prior art. The long term use of high osmolarity glucose solutions in peritoneal dialysis can result in irreversible changes to the peritoneal membrane due to the continuous high pressure differentials across the peritoneum. When a glucose solution with a low osmolarity is used in CAPD for greater than four hours glucose may be lost from the peritoneum to the serum, this is undesirable, particularly in diabetic patients. The present invention provides a method of applying an osmotic pressure over the peritoneum for greater than four hours without causing damage to the peritoneum whilst preventing appreciable loss of polysaccharide to the serum from the peritoneum and maintaining the flow of water from the serum to the peritoneum.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be described by way of example only and by reference to the attached drawings in which FIG. 1 is a flow diagram of the process described in Example 1;

FIG. 2 is a flow diagram of the process described in Example 2;

FIG. 3 is a flow diagram of the process described in Example 3;

FIG. 4 is a flow diagram of the process described in Example 4; and

FIG. 5 is a flow diagram of the process described in Example 5.

In the Examples OR means optical rotations.

The molecular weight distribution of the starch hydrolysate starting material which was used in Examples 1 and 2 is shown in Table 1. The starting material was found to have an M.sub.w of 6309 and an M.sub.n of 401.

EXAMPLE 1

Ethanol Fractionation

The fractionation procedure used to isolate the required molecular weight distribution of a maltodextrin syrup is given in FIG. 1. The precise technique to be used will of course be varied to take account of the quality and molecular weight distribution of the maltodextrin used as the starting material.

Aqueous ethanol (33 l at 85%v/v) was added, with stirring, to 37 l of a maltodextrin syrup (at 116.degree. OR=23 kg, dissolved maltodextrins). After settling the resulting Syrup I (5 l at 92.degree. OR) was drawn from the bottom outlet of the fractionator.

Aqueous ethanol (40 l at 85% v/v) was added, with stirring, to the Supernatant I. After settling the Supernatant II (84 l at 13.5.degree. OR) was decanted.

Aqueous ethanol (75 l at 85% v/v) and pyrogen free water (25 l) were added, with stirring, to the Syrup II (46 l at 50.25.degree. OR ). After settling the Supernatant III (103 l at 3.5.degree. OR ) was decanted.

Aqueous ethanol (54 l at 85% v/v) and pyrogen free water (14 l) were added, with stirring, to the resulting Syrup III (13 l at 104.degree. OR ). After settling the Supernatant IV (69 l at 3.4.degree. OR ) was decanted.

Aqueous ethanol (48 l at 85% v/v) and pyrogen free water (12 l) were added with stirring, to the resulting Syrup IV (12 l at 98.degree. OR ). After settling the required maltodextrin fraction, Syrup V, (10.51 at 102.4.degree. OR =5.5 kg dissolved maltodextrins) was drawn off. This represents 23.9% recovery of the maltodextrins present in the initial syrup. 3.8 kg of Syrup V was dissolved in pyrogen free water (25 l) and refluxed with stirring in the presence of 0.4 kg of activated carbon (Norit UK, GSX grade). The carbon was removed by filtration and the resulting syrup was used to prepare peritoneal dialysis solutions.

The M.sub.w of the product maltodextrin after carbon treatment was 18949 and the M.sub.n was 6316. The molecular weight distribution is shown in Table 2, 61% of the product lies within the range 5000 to 30000.

EXAMPLE 2

Ethanol Fractionation

The procedure of Example 1 was repeated using the quantities shown in FIG. 2. However, the carbon treatment was carried out by adding the activated carbon (Norit UK, grade GSX 5 kg) to the alcoholic Syrup V. The alcohol was removed by steam distillation and the carbon by depth filtration (Carlson Ford grade NA90). The resulting syrup was then spray dried.

The M.sub.w of the product maltodextrin was 12027 and the M.sub.n was 3447. The molecular weight distribution is shown in Table 3, 60% of the product lies within the range 5000 to 30000.

The M.sub.w of the product maltodextrin after carbon treatment was 12027 and the M.sub.n was 3447. The molecular weight distribution is shown in Table 3, 60% of the product lies within the range 5000 to 30000.

EXAMPLE 3

Ethanol Fractionation

The molecular weight distribution of the starting material is shown in Table 4. The starting material had an M.sub.w of 11534 and an M.sub.n of 586.

The procedure of Example 1 was repeated using the quantities shown in FIG. 3. However, the carbon treatment was carried out by adding the activated carbon (Norit UK, Grade GSX 60 kg) to the alcoholic syrup IV. The activated carbon was filtered off by depth filtration (Carlson Ford Grade `O` pads). A further carbon treatment was carried out on the syrup VI (15 kg Norit UK Grade GSX, filtered off using Carlson Ford Grade NA90 pads) during ethanol removal by steam distillation. The ethanol-free syrup was spray dried.

The M.sub.w of the product maltodextrin was 21838 and the M.sub.n was 7105. The molecular weight distribution is shown in Table 5, 58% of the product lies within the range 5000 to 30000.

EXAMPLE 4

Ethanol Fractionation

The molecular weight distribution of the starting material is shown in Table 6. The starting material had an M.sub.w of 12636 and an M.sub.n of 639.

The procedure of Example 1 was repeated using the quantities shown in FIG. 5. The carbon treatment was carried out by adding activated carbon (Norit UK, Grade GSX, 20 kg) to the alcoholic syrup IV. The carbon was filtered by depth filtration (Carlson Ford Grade `O` pads). Ethanol was removed from the final syrup (syrup V) by steam distillation and the aqueous product ion exchanged (mixed bed system), and spray dried. The mixed bed resin was Duolite A1725 in the hydroxyl form and C225H in the chloride form. (Duolite is a trade mark).

The M.sub.w of the product maltodextrin was 22020 and The M.sub.n was 7767. The molecular weight distribution is shown in Table 7, 60% of the product lies within the range 5000 to 30000.

EXAMPLE 5

Membrane Fractionation

a) A high molecular weight fractionation was carried out by passing 1.9 kg of starch hydrolysate, (molecular weight distribution, see Table 8), as a 10% w/v solution (20 liters) through a series of membranes. Polysulphone membranes with an approximate molecular weight cut-off of 20,000 and an area of 0.216 m.sup.2 were used. The feed flowrate was 6.6 liters/min at a temperature of 70.degree. C. The total solids level of the retained liquid was maintained at 10% w/v and the low molecular weight species were washed through the membrane. After 6.5 hours the concentration of carbohydrate in the permeate product stream leaving the ultrafiltration module was low, eg 0.5% w/v, (see Table 9) and the process was terminated. The high molecular weight residues were recovered from the membrane (0.2 kg, 10.5%) and the permeative low molecular weight product was isolated from the permeate (1.70 kg, 89.5%).

The molecular weight distribution of the product is shown in Table 10.

b) A low molecular weight fractionation was carried out by passing 0.64 kg of the low molecular weight product from Example 3a) as a 3.2% w/v solution (20 liters) through a series of membranes. Polysulphone membranes with an approximate molecular weight cut-off of 2,000 and an area S of 0.18 m.sup.2 were used. The feed flowrate was 6.6 liters/min at a temperature of 70.degree. C. The total solids level of the retained liquid was maintained at approximately 4.0% w/v and the low molecular weight species were washed through the membrane. After 95 minutes the concentration of carbohydrate in the permeate stream was zero (see Table 11) and the process was terminated. The undesired permeate product was recovered (0.465 kg, 73%) and the desired retained product was 0.166 kg (26%).

The molecular weight distribution of the product is shown in Table 12, 55% of the product lies within the range 5000 to 30000.

EXAMPLE 6

a) Membrane Fractionation

The procedure for Example 5a) was repeated using 2.0 kg of starch hydrolysate. Membranes were used with a cut-off value of 25000 an area of 0.144 m.sup.2. After 5.5 hours the concentration of the carbohydrate in the permeate was undetectable (see Table 13). The high molecular weight residues were recovered from the membrane (0.384 kg, 19.2%) and the permeative low molecular weight product was isolated from the permeate (1.613 kg, 80.6%). The molecular weight distribution of the permeate is given in Table 14. M.sub.w was found to be 4906 and M.sub.n determined as 744.

b) Ethanol Fractionation

1.7 kg of maltodextrin from Example 6a) in 53 liters of pyrogen free water was mixed with 132.5 liters of aqueous ethanol (85% v/v).

The syrup from the fractionation had an M.sub.w of 19712 and an M.sub.n of 4798. The molecular weight distribution is shown in Table 15, 55% of the product lies within the range 5000 to 30000.

EXAMPLE 7

Ethanol Fractionation

The procedure of Example 3 was carried out. Syrup V was isolated and the molecular weight distribution determined.

The M.sub.w of the product maltodextrin was 20211 and the M.sub.n was 2890. The molecular weight distribution is shown in Table 16, 50% of the product lies within the range 5000 to 30000.

EXAMPLE A

Two examples of peritoneal dialysis solutions are shown below. The ionic electrolytes behave ideally and therefore 1 mOsm/l is equivalent to 1 mmol/l. 

                                           1           2
          Sodium (mO sm/1)                 131         138
          Potassium (mO sm/1)               0           0
          Calcium (mO sm/1)                 1.8         1.78
          Magnesium (mO sm/1)               0.75        0.75
          Chloride (mO sm/1)               91          90
          Lactate (mO sm/1)                45          45
          Acetate (mO sm/1)                --          --
          Bisulphite (mO sm/1)             --          --
          Total Electrolyte               269.6       275.5
          Osmolarity (mO sm/1)
          Glucose polymer (I) (mO sm/1)    12.9        12.9
                                         (50 g/l)    (50 g/l)
          Total Osmolarity                282.5       288.4


                         TABLE 1
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                   165                       0.00
                   167                       2.50
                   172                       5.00
                   178                       7.50
                   184                      10.00
                   191                      12.50
                   199                      15.00
                   207                      17.50
                   216                      20.00
                   226                      22.50
                   237                      25.00
                   249                      27.50
                   262                      30.00
                   276                      32.50
                   291                      35.00
                   307                      37.50
                   326                      40.00
                   346                      42.50
                   366                      45.00
                   391                      47.50
                   419                      50.00
                   446                      52.50
                   488                      55.00
                   532                      57.50
                   598                      60.00
                   681                      62.50
                   837                      65.00
                  1099                      67.50
                  1570                      70.00
                  2328                      72.50
                  3436                      75.00
                  4915                      77.50
                  6789                      80.00
                  7135                      82.50
                  12074                     85.00
                  13825                     87.50
                  20735                     90.00
                  27447                     92.50
                  37044                     95.00
                  53463                     97.50
                 199559                    100.00


                         TABLE 2
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                   296                       0.00
                  1231                       2.50
                  1756                       5.00
                  2279                       7.50
                  2795                      10.00
                  3291                      12.50
                  3771                      15.00
                  4246                      17.50
                  4722                      20.00
                  5203                      22.50
                  5696                      25.00
                  6196                      27.50
                  6718                      30.00
                  7247                      32.50
                  7809                      35.00
                  8378                      37.50
                  8986                      40.00
                  9607                      42.50
                  10272                     45.00
                  10960                     47.50
                  11695                     50.00
                  12472                     52.50
                  13295                     55.00
                  14184                     57.50
                  15126                     60.00
                  16162                     62.50
                  17274                     65.00
                  18499                     67.50
                  19872                     70.00
                  21352                     72.50
                  23122                     75.00
                  25084                     77.50
                  27319                     80.00
                  30070                     82.50
                  33400                     85.00
                  37527                     87.50
                  42867                     90.00
                  50412                     92.50
                  61686                     95.00
                  82648                     97.50
                 288182                    100.00


                         TABLE 3
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                   183                       0.00
                   484                       2.50
                   874                       5.00
                  1292                       7.50
                  1695                      10.00
                  2082                      12.50
                  2460                      15.00
                  2836                      17.50
                  3215                      20.00
                  3595                      22.50
                  3986                      25.00
                  4382                      27.50
                  4786                      30.00
                  5204                      32.50
                  5627                      35.00
                  6072                      37.50
                  6519                      40.00
                  6994                      42.50
                  7473                      45.00
                  7982                      47.50
                  8499                      50.00
                  9048                      52.50
                  9611                      55.00
                  10212                     57.50
                  10836                     60.00
                  11502                     62.50
                  12208                     65.00
                  12955                     67.50
                  13777                     70.00
                  14637                     72.50
                  15626                     75.00
                  16708                     77.50
                  17905                     80.00
                  19298                     82.50
                  20957                     85.00
                  22960                     87.50
                  25476                     90.00
                  29002                     92.50
                  34287                     95.00
                  44550                     97.50
                 299523                    100.00


                         TABLE 4
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                   146                       0.00
                   157                       2.50
                   173                       5.00
                   192                       7.50
                   213                      10.00
                   235                      12.50
                   259                      15.00
                   285                      17.50
                   313                      20.00
                   343                      22.50
                   378                      25.00
                   411                      27.50
                   450                      30.00
                   489                      32.50
                   536                      35.00
                   583                      37.50
                   636                      40.00
                   695                      42.50
                   755                      45.00
                   837                      47.50
                   920                      50.00
                  1036                      52.50
                  1161                      55.00
                  1350                      57.50
                  1590                      60.00
                  1919                      62.50
                  2393                      65.00
                  3094                      67.50
                  4176                      70.00
                  5731                      75.00
                  7802                      75.00
                  10354                     77.50
                  13393                     80.00
                  17014                     82.50
                  21436                     85.00
                  27030                     87.50
                  34348                     90.00
                  44586                     92.50
                  60087                     95.00
                  89965                     97.50
                 578156                    100.00


                         TABLE 5
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                  1394                       2.50
                  2060                       5.00
                  2644                       7.50
                  3199                      10.00
                  3751                      12.50
                  4299                      15.00
                  4856                      17.50
                  5421                      20.00
                  6003                      22.50
                  6597                      25.00
                  7208                      27.50
                  7841                      30.00
                  8497                      32.50
                  9175                      35.00
                  9881                      37.50
                  10615                     40.00
                  11385                     42.50
                  12189                     45.00
                  13033                     47.50
                  13924                     50.00
                  14870                     52.50
                  15874                     55.00
                  16947                     57.50
                  18096                     60.00
                  19333                     62.50
                  20685                     65.00
                  22167                     67.50
                  23793                     70.00
                  25616                     72.50
                  27661                     75.00
                  29973                     77.50
                  32624                     80.00
                  35745                     82.50
                  39445                     85.00
                  44003                     87.50
                  49720                     90.00
                  57401                     92.50
                  68831                     95.00
                  90432                     97.50


                         TABLE 6
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                   146                       0.00
                   156                       2.50
                   175                       5.00
                   197                       7.50
                   223                      10.00
                   250                      12.50
                   279                      15.00
                   311                      17.50
                   345                      20.00
                   381                      22.50
                   420                      25.00
                   462                      27.50
                   506                      30.00
                   555                      32.50
                   603                      35.00
                   662                      37.50
                   721                      40.00
                   792                      42.50
                   875                      45.00
                   971                      47.50
                  1099                      50.00
                  1269                      52.50
                  1496                      55.00
                  1827                      57.50
                  2320                      60.00
                  3043                      62.50
                  4107                      65.00
                  5556                      67.50
                  7396                      70.00
                  9581                      75.00
                  12065                     75.00
                  14880                     77.50
                  18153                     80.00
                  21986                     82.50
                  26590                     85.00
                  32293                     87.50
                  39532                     90.00
                  49285                     92.50
                  63509                     95.00
                  89961                     97.50
                 439968                    100.00


                         TABLE 7
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                  1586                       2.50
                  2290                       5.00
                  2882                       7.50
                  3443                      10.00
                  3991                      12.50
                  4545                      15.00
                  5110                      17.50
                  5694                      20.00
                  6302                      22.50
                  6931                      25.00
                  7587                      27.50
                  8263                      30.00
                  8965                      32.50
                  9692                      35.00
                  10441                     37.50
                  11218                     40.00
                  12030                     42.50
                  12878                     45.00
                  13761                     47.50
                  14691                     50.00
                  15671                     52.50
                  16705                     55.00
                  17805                     57.50
                  18982                     60.00
                  20244                     62.50
                  21615                     65.00
                  23120                     67.50
                  24766                     70.00
                  26584                     72.50
                  28624                     75.00
                  30930                     77.50
                  33568                     80.00
                  36623                     82.50
                  40240                     85.00
                  44626                     87.50
                  50148                     90.00
                  57346                     92.50
                  67788                     95.00
                  86399                     97.50


                         TABLE 8
                        Starch Hydrolysate
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                   146                       0.00
                   160                       2.50
                   176                       5.00
                   195                       7.50
                   217                      10.00
                   240                      12.50
                   264                      15.00
                   291                      17.50
                   322                      20.00
                   354                      22.50
                   390                      25.00
                   428                      27.50
                   470                      30.00
                   511                      32.50
                   558                      35.00
                   605                      37.50
                   657                      40.00
                   714                      42.50
                   772                      45.00
                   852                      47.50
                   934                      50.00
                  1050                      52.50
                  1185                      55.00
                  1398                      57.50
                  1688                      60.00
                  2104                      62.50
                  2708                      65.00
                  3617                      67.50
                  4870                      70.00
                  6517                      75.00
                  8552                      75.00
                  10946                     77.50
                  13729                     80.00
                  17036                     82.50
                  21022                     85.00
                  25964                     87.50
                  32324                     90.00
                  40911                     92.50
                  53516                     95.00
                  76329                     97.50
                 356145                    100.00


        TABLE 9
           Pressure          Permeate Flow  Feed Soln  Permeate
           in    out  Temp       Rate         Concn      Conc
    Time      Bar     .degree. C.      1/min        % w/v      % w/v
      0    4.6   3.4   64            on total recycle
      1     "     "    64         190          10.5        7
      1.5   "     "    68         192          10          6.5
      2     "     "    71         198           9          5
      3     "     "    69         166           8          3.5
      4     "     "    69         165           6.75       2.25
      6     "     "    70         148           6          1
      6.5   "     "    65         140           8          0.5


                         TABLE 10
                        Permeate (Ex 5(a))
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                   146                       0.00
                   169                       2.50
                   205                       5.00
                   247                       7.50
                   285                      10.00
                   323                      12.50
                   362                      15.00
                   403                      17.50
                   444                      20.00
                   488                      22.50
                   533                      25.00
                   581                      27.50
                   630                      30.00
                   681                      32.50
                   734                      35.00
                   787                      37.50
                   845                      40.00
                   906                      42.50
                   966                      45.00
                  1038                      47.50
                  1117                      50.00
                  1196                      52.50
                  1303                      55.00
                  1423                      57.50
                  1567                      60.00
                  1758                      62.50
                  2003                      65.00
                  2308                      67.50
                  2720                      70.00
                  3287                      72.50
                  4080                      75.00
                  5156                      77.50
                  6535                      80.00
                  8280                      82.50
                  10326                     85.00
                  12731                     87.50
                  15631                     90.00
                  19283                     92.50
                  24378                     95.00
                  32986                     97.50
                  93587                    100.00


           TABLE 11
               Pressure         Permeate Flow Feed Soln Permeate
               in    out  Temp      Rate        Concn     Conc
      Time        Bar     .degree. C.     1/min       % w/v    %. w/v
      0        5.4   4.6   70        390          3.25      1.75
     15 mins   5.4   4.6   70        400          3.5       1.5
     35 mins   5.4   4.6   71        300          5.0       2.0
     60 mins   5.4   4.6   70        280          4.25      1
     95 mins   5.4   4.6   69        280          3.0       0


                         TABLE 12
                       Retentate (Ex 5(b))
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                   186                       0.00
                   834                       2.50
                  1339                       5.00
                  1837                       7.50
                  2410                      10.00
                  3090                      12.50
                  3869                      15.00
                  4717                      17.50
                  5613                      20.00
                  6540                      22.50
                  7492                      25.00
                  8458                      27.50
                  9433                      30.00
                  10414                     32.50
                  11398                     35.00
                  12385                     37.50
                  13374                     40.00
                  14384                     42.50
                  15406                     45.00
                  16449                     47.50
                  17519                     50.00
                  18611                     52.50
                  19754                     55.00
                  20917                     57.50
                  22167                     60.00
                  23437                     62.50
                  24832                     65.00
                  26283                     67.50
                  27852                     70.00
                  29576                     72.50
                  31415                     75.00
                  33457                     77.50
                  35747                     80.00
                  38449                     82.50
                  41731                     85.00
                  45703                     87.50
                  50765                     90.00
                  57945                     92.50
                  69100                     95.00
                  90766                     97.50
                 410452                    100.00


       TABLE 13
           Pressure          Permeate Flow  Feed Soln  Permeate
           in    out  Temp       Rate         Concn      Conc
    Time      Bar     .degree. C.      1/min        % w/v      % w/v
    0.75   4.7   3.3   67         225           9.5        5.0
    1.25   4.7   3.8   68         184          10.5        5.5
    2.50   4.8   3.2   70         150           9.0        4.0
    3.50   4.8   3.2   70         144           8.0        1.5
    4.50   4.8   3.2   69         130           6.5        0.5
    5.50   4.8   3.2   69         123           6.0        0


                         TABLE 14
                         Permeate (Ex 6)
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                   146                       0.00
                   170                       2.50
                   207                       5.00
                   251                       7.50
                   293                      10.00
                   335                      12.50
                   378                      15.00
                   423                      17.50
                   469                      20.00
                   516                      22.50
                   566                      25.00
                   616                      27.50
                   660                      30.00
                   720                      32.50
                   773                      35.00
                   827                      37.50
                   882                      40.00
                   939                      42.50
                  1004                      45.00
                  1070                      47.50
                  1135                      50.00
                  1226                      52.50
                  1320                      55.00
                  1418                      57.50
                  1567                      60.00
                  1717                      62.50
                  1947                      65.00
                  2218                      67.50
                  2566                      70.00
                  3056                      72.50
                  3718                      75.00
                  4671                      77.50
                  5959                      80.00
                  7656                      82.50
                  9753                      85.00
                  12271                     87.50
                  15332                     90.00
                  19237                     92.50
                  24688                     95.00
                  34400                     97.50
                  98105                    100.00


                         TABLE 15
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                   170                       0.00
                   845                       2.50
                  1292                       5.00
                  1674                       7.50
                  2044                      10.00
                  2429                      12.50
                  2841                      15.00
                  3283                      17.50
                  3754                      20.00
                  4269                      22.50
                  4805                      25.00
                  5361                      27.50
                  5958                      30.00
                  6583                      32.50
                  7232                      35.00
                  7937                      37.50
                  8666                      40.00
                  9447                      42.50
                  10273                     45.00
                  11129                     47.50
                  12062                     50.00
                  13024                     52.50
                  14053                     55.00
                  15147                     57.50
                  16281                     60.00
                  17537                     62.50
                  18860                     65.00
                  20264                     67.50
                  21839                     70.00
                  23542                     72.50
                  25408                     75.00
                  27488                     77.50
                  29900                     80.00
                  32694                     82.50
                  36020                     85.00
                  40183                     87.50
                  45419                     90.00
                  52731                     92.50
                  64063                     95.00
                  85249                     97.50
                 349210                    100.00


                         TABLE 16
                  Molecular Weight Distribution
                MOLECULAR                INTEGRAL
                 WEIGHTS               DISTRIBUTION
                   147                       0.00
                   354                       2.50
                   627                       5.00
                   918                       7.50
                  1243                      10.00
                  1602                      12.50
                  1996                      15.00
                  2431                      17.50
                  2908                      20.00
                  3428                      22.50
                  3990                      25.00
                  4591                      27.50
                  5232                      30.00
                  5924                      32.50
                  6653                      35.00
                  7417                      37.50
                  8230                      40.00
                  9092                      42.50
                  9990                      45.00
                  10946                     47.50
                  11966                     50.00
                  13032                     52.50
                  14178                     55.00
                  15407                     57.50
                  16704                     60.00
                  18105                     62.50
                  19643                     65.00
                  21999                     67.50
                  23093                     70.00
                  25087                     72.50
                  27332                     75.00
                  29844                     77.50
                  32692                     80.00
                  35966                     82.50
                  39805                     85.00
                  44449                     87.50
                  50079                     90.00
                  57437                     92.50
                  67881                     95.00
                  86087                     97.50
                 331467                    100.00


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